I made an olive oil rebatch yesterday and added peppermint as an accent. Someone told me this herb would hold it's color in soap. It looked beautiful coming out of the molds, almost pure white with beautiful green flecks, but today it has brown spots all over and the soap itself has darkened from white to a yukky looking yellowish. I am thinking of melting the whole batch back down and putting in something to color it. Suggestions anyone? Do you think this would work?